Conventional method for transmitting computer video signals utilizes a plurality of transmission lines such that each of the red video signal (R), the green video signal (G), the blue video signal (B), horizontal synchronous signal (Hsync), and vertical synchronous signal (Vsync) is transmitted by one transmission line. However, due to the progressing of the computer technology, there is a trend to decrease the number of transmission lines, so as to reduce the volume and cost of the transmission cable.